Extremum seeking applied to the plasma control system of the Frascati Tokamak Upgrade

A new extremum seeking technique and its application to maximize RF heating on FTU

“…For the proposed approach we formally state convergence properties of the control law, while making mild assumptions on the unknown function to be minimized in the ideal case. Finally, we show that based on this more solid theoretical framework, the effectiveness of the new scheme on the Tokamak plasma control problem in [3,4] is highly increased, both in terms of performance and robustness, as compared to the previous results of [3].…”

“…Nevertheless, the problem with these early solutions was slow convergence and lack of any guarantee. Later experiments employed a modified extremum seeking technique to solve the problem [3], which showed increased performance and robustness in experiments, even though from the experimental results it was clear that the algorithm used could be improved. Implementation issues arising from the use of multiple antennas were reported in [4].…”

“…In [3], experimental results showed that using a generalization of the classical extremum seeking scheme of [5] could reduce significantly the reflected power thus making the heating process more effective. On the other hand, the performance of the extremum seeking controller in [3] was very sensitive to the control parameter values, and in some cases it induced violent and undesirable plasma oscillations, whereas in other ones the convergence to the minimum was too slow. This motivated the authors to improve the robustness and the performance of the previous extremum seeking algorithm.…”

“…In this paper we use the application study and the experimental results of [3,4] to improve the performance and robustness of the scheme, providing a more rigorous theoretical background for the ideal control scheme in Theorem 1.…”

Maximization of the lower hybrid power coupling in the Frascati Tokamak Upgrade via extremum seeking

“…Extremum seeking techniques have also been recently used in a different context within the plasma control area (Ou et al, 2007), but the problem addressed here is different in nature from that one addressed in Ou et al (2007). Preliminary results about this paper have been reported in Centioli et al (2005). The paper is structured as follows: Section 2 describes the problem setting and the adopted extremum seeking scheme.…”